The Empire State Building towers over the Manhattan skyline as tourists gather on the observation deck of Rockefeller Center on February 13, 2012 in New York City. The owner of the Empire State Building, Malkin Holdings, plans to raise up to $1 billion in an initial public offering on the 102 story Manhattan landmark. (Photo by John Moore/Getty Images)

SI bodypaint model, soccer player Alex Morgan (L) attends SI Swimsuit On Location hosted by Haze Nightclub at the Aria Resort & Casino at CityCenter on February 15, 2012 in Las Vegas, Nevada. (Photo by Michael Loccisano/Getty Images for Sports Illustrated)

Australian Motorcross rider and member of the Crusty Demons, Robbie Marshall jumps over a helicopter with rotating blades and a Formula 1 car at Avalon Airport on February 22, 2012 in Melbourne, Australia. (Photo by Scott Barbour/Getty Images)

Commander, a German Shepherd adult (L) and Ziva, a German Shepherd puppy attend as American Kennel Club announces Most Popular Dogs in the U.S. at American Kennel Club Offices on February 28, 2012 in New York City. (Photo by Gary Gershoff/Getty Images for AKC)

Military staff members of the German Bundeswehr check an Eurocopter Tiger military attack helicopter at the Eurocopter plant on March 8, 2012 in Donauworth, Germany. EADS, the parent company of Eurocopter as well as airplane manufacturer Airbus, is scheduled to announce financial results for 2011 today. (Photo by Johannes Simon/Getty Images)

Dunnottar Castleis a ruined medieval fortress located upon a rocky headland on the north-east coast of Scotland, about 3 kilometres (1.9 mi) south of Stonehaven. The surviving buildings are largely of the 15th and 16th centuries, but the site is believed to have been fortified in the Early Middle Ages. Dunnottar has played a prominent role in the history of Scotland through to the 18th-century Jacobite risings because of its strategic location and the strength of its situation. Dunnottar is best known as the place where the Honours of Scotland, the Scottish crown jewels, were hidden from Oliver Cromwell's invading army in the 17th century. The property of the Keiths from the 14th century, and the seat of the Earl Marischal, Dunnottar declined after the last Earl forfeited his titles by taking part in the Jacobite rebellion of 1715. The castle was restored in the 20th century and is now open to the public.

A man carrying an axe walks past a house marked with bullet holes in Gyallesu district after recent clashes between Shi'ites and the army in Zaria, Kaduna state, Nigeria, February 3, 2016. Sectarian tensions are rising in Nigeria's Muslim north, where hundreds of Shi'ites were killed in clashes with the army in the town of Zaria in December, according to Shi'ites and rights groups. Following the clashes, bulldozers sent by the state levelled Shi'ite shrines, a cemetery and offices in the deeply divided town. The region is already grappling with an insurgency waged by the jihadist Boko Haram group. (Photo by Afolabi Sotunde/Reuters)

Li Guoqiang talks on his phone outside his house at Guangfuli neighbourhood, in Shanghai, China, April 1, 2016. Li, 38, is a deliveryman who rents a place at Guangfuli. In a corner of Shanghai, surrounded by a cement wall, lies one of the world's most valuable fields of debris and garbage. On paper, the Guangfuli neighbourhood is a real estate investor's dream: a plot in the middle of one of the world's most expensive and fast-rising property markets. But the reality is more like a developer's nightmare, thanks to hundreds of people living there who have refused to budge from their ramshackle homes for nearly 16 years as the local authority sought to clear the land for new construction. (Photo by Aly Song/Reuters)